Prime all day long. I don’t care how much prep time you have. Nobody can beat Superboy one on one. Well, so far nobody has gotten close. Dude is so strong he punched reality itself into a state of confusion.
You gave all of the essential information except for one thing, the writer. Things like this seem to come down to the writer’s fondness for the characters. Objectively, I think Prime would have it but as he’s written now BWL would win.